Thorben Müller

Embalmed and fresh frozen human bones in orthopedic cadaveric studies: which bone is authentic and feasible?

Background and purpose The most frequently used bones for mechanical testing of orthopedic and trauma devices are fresh frozen cadaveric bones, embalmed cadaveric bones, and artificial composite bones. Even today, the comparability of these different bone types has not been established. Methods We tested fresh frozen and embalmed cadaveric femora that were similar concerning age, sex, bone mineral density, and stiffness. Artificial composite femora were used as a reference group. Testing parameters were pullout forces of cortex and cancellous screws, maximum load until failure, and type of fracture generated. Results Stiffness and type of fracture generated (Pauwels III) were similar for all 3 bone types (fresh frozen: 969 N/mm, 95% confidence interval (CI): 897–1,039; embalmed: 999 N/mm, CI: 875–1,121; composite: 946 N/mm, CI: 852–1,040). Furthermore, no significant differences were found between fresh frozen and embalmed femora concerning pullout forces of cancellous screws (fresh frozen: 654 N, CI: 471–836; embalmed: 595 N, CI: 365–823) and cortex screws (fresh frozen: 1,152 N, CI: 894–1,408; embalmed: 1,461 N, CI: 880–2,042), and axial load until failure (fresh frozen: 3,427 N, CI: 2,564–4290; embalmed: 3,603 N, CI: 2,898–4,306). The reference group showed statistically significantly different results for pullout forces of cancellous screws (2,344 N, CI: 2,068–2,620) and cortex screws (5,536 N, CI: 5,203–5,867) and for the axial load until failure (> 7,952 N). Interpretation Embalmed femur bones and fresh frozen bones had similar characteristics by mechanical testing. Thus, we suggest that embalmed human cadaveric bone is a good and safe option for mechanical testing of orthopedic and trauma devices.

Use of the gamma3™ nail in a teaching hospital for trochanteric fractures: mechanical complications, functional outcomes, and quality of life

BackgroundTrochanteric fractures are common fractures in the elderly. Due to characteristic demographic changes, the incidence of these injuries is rapidly increasing. Treatment of these fractures is associated with high rates of complications. In addition, the long-term results remain poor, with high morbidity, declines in function, and high mortality. Therefore, in this study, complication rates and patients’ outcomes were evaluated after fixation of geriatric trochanteric fractures using the Gamma3™ nail.MethodsPatients aged 60 years old or older, with pertrochanteric and subtrochanteric femoral fractures, were included. Patients with polytrauma or pathological fractures were excluded. Age, sex, and fracture type were collected on admission. In addition, data were recorded concerning the surgeon (resident vs. consultant), time of operation, and local or systemic perioperative complications. Complications were also collected at the 6- and 12-month follow-ups after trauma. Barthel Index, IADL, and EQ-5D measurements were evaluated retrospectively on admission, as well as at discharge and during the follow-up.ResultsNinety patients were prospectively included between April 2009 and September 2010. The patients’ average age was 81 years old, and their average ASA score was 3. The incision/suture time was 53 min (95% CI 46–60 min). Hospital mortality was 4%, and overall mortality was 22% at the 12-month follow-up. Eight local complications occurred (4 haematomas, 1 deep infection, 1 cutting out, 1 irritation of the iliotibial tract, 1 periosteosynthetic fracture). The incidence of relevant systemic complications was 6%. Forty-two percent of the patients were operated on by residents in training, without significant differences in duration of surgery, complication rate, or mortality rate. The Barthel Index (82 to 71, p < .001), IADL (4.5 to 4.3, p = .0195) and EQ-5-D (0.75 to 0.66, p = .068) values did not reach pre-fracture levels during the follow-up period of 12 months.ConclusionThe results showed a relatively low complication rate using the Gamma3™ nail, even if the nailing was performed by residents in training. The high mortality, declines in function, and low quality of life could probably be attributed to pre-existing conditions, such as physical status.In summary, the Gamma3™ nail seems to be a useful implant for the nailing of trochanteric fractures, although further studies are necessary comparing different currently available devices.

A comparison of the treatment of severe injuries between the former East and West German States.

BACKGROUND The annual number of persons killed in road-traffic accidents in Germany declined by 36% from 2001 to 2008, yet official traffic statistics still reveal a marked difference in fatalities between the federal states of the former East and West Germany twenty years after German reunification. METHODS We retrospectively analyzed data from the Trauma Registry of the German Trauma Society (Deutsche Gesellschaft für Unfallchirurgie; TR-DGU). Patients receiving primary treatment that had an Injury Severity Score (ISS) of 9 or above were analyzed separately depending on whether they were treated in the former East Germany or the former West Germany. RESULTS Data were obtained from a total of 26 866 road-accident trauma cases. With Berlin excluded, 2597 cases (10.2%) were from the former East Germany (EG), and 22 966 (89.9%) were from the former West Germany (WG). The percentage of the population living in these two parts of the country is 16.7% and 83.3%, respectively. The two groups did not differ significantly in either the mortality of injuries (EG 15.8%, WG 15.7%) or in the standardized mortality rate (0.89 [EG] vs. 0.88 [WG]). Over the years 2002-2008, the mean time to arrival of the emergency medical services on the scene was 19 minutes (EG) vs. 17 minutes (WG), and the mean time to arrival in hospital was 76 minutes (EG) vs. 69 minutes (WG). CONCLUSION Among the hospitals whose cases are included in the TR-DGU, there is no significant difference between the former East and West Germany with respect to mortality or any other clinically relevant variable. Hypothetically, the higher rate of death from road-traffic accidents in the former East Germany, as revealed by national traffic statistics, might be attributable to a difference in the quality of care received by trauma patients, but no such difference was found. Other potential reasons for it might be poorer road conditions, more initially fatal accidents, and lower accessibility of medical care in less densely populated areas.